Curve-drawing instrument.



No.'841,222. PATENTED JAN. 15, 1907. F. H. BOWMAN.

CURVE DRAWING INSTRUMENT.

APPLICATION FILED DEC. 1. 1905.

Inventor Francis H. Bowman Witnesses UNITED STATES PATENT OFFICE.

FRANCIS H. BOWMAN, OF PITITSFIELD, MASSACHUSET'lS, ASSIGNOR TO STANLEY-C. l. ELEC"RIC MANUFACTURING COMPANY, A CORPORA- TION OF NEW JERSEY.

Specification of Letters Patent.

Patented Jan. 15, 1907.

Application filed December 1, 1905. Serial No- 289,839.

To (1/7] whom, it may concern.-

Be it known that I, FRANCIS H. BOWMAN, a citizen of the United States, residing at Pittsfield, county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Ourve-Drawing Instruments, of which the following is a specification.

This invention relates to marking devices of the capillary type in which a writing fluid is continuously fed to the marking-tip, and has for its object the provision of a device of this character in which an ade uate and con tinuous flow of fluid is positive y maintained Without danger of blotting or flooding and in which there is a minimum amount of evaporation.

In carryim out my invention I provide as a receptacle for the writing fluid a glass tube with an integral reservoir below the markingpoint and having an internal capillary feed through a transparent tube. The reservoirtube is entirely closed except for a filling-orifice, and a metallic writing-tip is sealed in one end and has a transparent capillary tube extending from its inner end down into the fluid. I also provide a detachable clip provided with a trunnion whereby the pen may be mounted to move easily.

My invention consists, therefore, in the features of construction and in the arrangement and combination of elements hereinafter set forth, and particularly pointed out in the claims annexed to and forming a part of this specification.

In the drawings, Figure 1 is an elevation of a device embodying my invention. Fig. 2 is a longitudinal section thereof, and Fig. 3 is a cross-section of the same.

Referring to the drawings, 1 is a receptacle for the writing fluid, preferably of glass, and may be of any desired form. I prefer, however, to make it in the form of a tube closed at the ends and bent at an angle so as to be substantially L shaped. By its angular shape the reservoir is below the point or marker, andthe ink will not spill under jars or vibration. A filling-orifice is provided at any convenient point, as at 2. The metallic tip of the pen 3 has a fine bore and is preferably of some platinum alloy, such as platinum iridium. This metal is easily and efficiently sealed into glass and is also by reason of its hardness a desirable metal for a pen.

This tip 3 is first sealed into the glass capil- 5 5 lary 4 and then both are sealed into the combined reservoir and protecting-tube. The capillary tube 4 is bent to conform to the shape of the tube 1 and extends down into the fluid 5 and adjacent to the closed end of the tube. This tube 4 is likewise of glass and is therefore transparent, thus permitting easy' inspection. In starting the pen it is anadvantage to be able to see the interior of the capillary tube throughout its length, as some- 6 times air-bubbles or sediment matter get drawn into the capillary, and I consider it of great convenience to be able to see Where such are. Dislodgment tLus becomes easy.

As a means for attaching the pen to the recording device on which it is to be used I provide a detachable metallic clip 6, having prongs 7 and 8 and provided with a trunnion 9, whereby the pen may be pivoted, if desired, so as to be moved away from the recording-sheet and effect a yielding marking contact with the recording-surface.

Another very important feature is that the glass capillary tube is protected by the surrounding heavy glass reservoir throughout 8c its whole extent.

It will be seen that I have provided a very cheap and eflicient marking-pen. By making the receptacle of glass it can easily be made into any desired shape and size, and it will always be possible to know just how much fluid remains in the receptacle and where any foreign or dry matter has lodged.

The short metallic tip affords a very durable and reliable marking-pen and can be easily go cleaned by a fine short wire with no bends to interfere, a point which will be easily appreciated by those who have used capillarypens, while the capillary tube extending down into the receptacle and the shape of the device as 5 a whole assure a positive feed without danger of flooding or blotting.

By making the receptacle entirely closed, except for a small filling-orifice, a minimum of evaporation is assured, while at the same time it is impossible for the fluid to be spilled by jarring or other accident to the receptacle during adjustment or when in use.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. A marking-pen comprising a glass reoe tacle'closed at one endand having a meta lic ink-duet sealed in the other end.

2. A marking-pen comprising a glass receptacle closed at one .end, and an inl -duct provided with a metallic tip sealed 1n the other end.

3. .A marking-pen comprising a bent glass receptacle closed at one end, and an-ink-duct sealed in the other end and extending Within the1 same and terminating adjacent the closed en 4. A marking-pen comprising a bent-glass receptacle closed at one end, an ink-duct sealed in the other end, and means for pivotally mounting said pen.

5. A marking-pen comprising a bent glass receptacle closed at one end, an ink-duct provided with a metallic tip sealed within the same and terminating adjacent the closed end, and means intermediate the ends for pivotally mounting said pen.

6. A marking-pen comprising a bent glass tube closed at one end, a metallic capillary tipsealed in theother end, and a larger tube secured-to the inner .end of said' tip and termisecured to the inner end of said tip and terminating adjacent the closed end, and a detachable clip lntermediate the ends of said glass tube provided; with means for pivotally mounting'the same.

In witness whereof I have hereunto set hand this 28th day of November, 1905. FRANCIS H. BOWMAN.

Witnesses 5 FoRBEs T. C LLEN, F. M. PLATT. 

